Oh it's absolutely true. Provided the pain you are experiencing isn't in your hands, eyes/head or is brutally bad, the distraction provided by game-playing is an incredibly effective pain reliever.

It's why gaming can be so relaxing for people who have physically demanding jobs. Youl come home, achey and sore, but spend a while playing a game and you completely forget the discomfort you're feeling.
Or if you're recovering from an injury, the distraction of a game can make spending all day with a nasty pain extremely bearable.

It even helps when you're just sick. Ailments are distressing largely because we are acutely aware of them, so get distracted and it can be like a miracle cure (albeit temporarily).

— You know the very powerful and the very stupid have one thing in common. They don't alter their views to fit the facts, they alter the facts to fit their views, which can be uncomfortable if you happen to be one of the facts that needs altering.